1. Field of the Invention
This invention relates generally to a dental panoramic radiographic apparatus and more particularly to an apparatus capable of concurrently taking a normal picture of a temporomandibular joint in addition to a picture of the tooth, jaw and face regions with one apparatus.
2. Prior Art
As well known, a conventional dental panoramic radiographic apparatus makes use of a curved plane section of an object. The apparatus panoramically pictures the entire jaw region and not only makes it possible to collectively diagnose individual and all the teeth and their ambient state of bone but also greatly contributes to a radiographic diagnosis of the face region such as an eye orbit, nasal cavity, otic cavity, etc. in addition to the tooth and jaw regions.
When medical treatment is given to a disease in the jaw region, it is an established fact from the viewpoint of dental examination of the disease that a dentist should have detailed information on the function and construction of a temporomandibular joint. For this reason, a normal radiographic picture of the temporomandibular joint is simultaneously taken in combination with the panoramic radiographic diagnosis mentioned above. As the method which has heretofore been practiced for taking a normal picture of the temporomandibular joint, there are provided various types of special photographing which use a panoramic radiographic apparatus commercially obtainable. But since all such types need special photographic attachments, special cassettes, etc. to be used with an existing apparatus, preparations by an operator for sets of such special photographic attachments, a particular posture of a patient to be pictured to correspond to the sets, and technique of photographing cause inconvenience to the operator and the patient. When comparing such inconvenience in the apparatus with the importance of examining the function of temporomandibular joint, the generalization of the use of the apparatus is not sufficient. In addition thereto, because the apparatus cannot picture a curved plane section of the temporomandibular joint, the temporomandibular joint and the other cranium constituting bones are overlapped and enlarged into one piece of X-ray picture, with the result that the picture disadvantageously becomes indistinct and lacks clearness.